Process for removal of polymer foams from nickel-coated substrates

Abstract

The method of the invention produces nickel structures from nickel-coated polymer substrates. The nickel-coated polymer substrate has a nickel outer layer and initially has a temperature where the outer nickel layer lacks burst openings. Rapidly exposing the nickel-coated polymer substrate to a temperature of at least about 600° C. thermally decomposes the polymer substrate and bursts holes through the outer nickel layer. The gases resulting from the thermally decomposed polymer substrate escape through the holes through the outer nickel layer to leave a nickel structure. Finally, annealing the nickel structure increases strength of the nickel structure to produce a ductile foam product.

We claim: 
     
       1. A method of producing nickel structures comprising the steps of: a) providing a nickel-coated polymer substrate, said nickel-coated polymer substrate having an outer nickel layer and said nickel-coated polymer substrate being at a temperature where said outer nickel layer lacks burst openings,   b) heating said nickel-coated polymer substrate by exposing said nickel-coated polymer substrate to a temperature of at least about 600° C. in less than about five seconds to thermally decompose polymer substrate and cause gaseous decomposition products of the polymer to form a large internal pressure and burst holes through said outer nickel layer of said nickel-coated polymer substrate,   c) discharging gases from the thermally decomposed polymer substrate through said holes through said outer nickel layer to leave a nickel structure, and   d) annealing said nickel structure to increase strength of said nickel structure.   
     
     
       2. The method of claim 1 wherein said heating includes exposing said nickel-coated polymer substrate to a temperature of at least 900° C. to anneal the nickel structure. 
     
     
       3. The method of claim 2 wherein said heating includes sending said nickel-coated polymer substrates through a continuous furnace and said annealing includes sending said nickel structure through a belt furnace. 
     
     
       4. The method of claim 1 wherein a protective insert maintains temperature of the nickel-coated polymer substrate below the melting temperature of the polymer prior to said heating. 
     
     
       5. The method of claim 1 wherein a protective insert maintains temperature of the nickel-coated polymer substrate below about 200° C. prior to said heating. 
     
     
       6. The method of claim 1 wherein said heating is to a temperature of at least 600° C. in less than three seconds. 
     
     
       7. The method of claim 1 wherein nickel carbonyl-coated polymer substrate is heated. 
     
     
       8. The method of claim 1 wherein said nickel-coated polymer substrate heats to a temperature of 700° C. in less than three seconds. 
     
     
       9. The method of claim 1 wherein said heating includes exposing said nickel-coated foam to a hot zone of a single furnace maintained at a temperature between about 800° C. and about 1200° C. 
     
     
       10. A method of producing nickel structures comprising the steps of: a) providing a nickel-coated polymer substrate, said nickel-coated polymer substrate having an outer nickel layer and a temperature of less than about 200° C.,   b) heating said nickel-coated polymer substrate by exposing said nickel-coated polymer substrate to a temperature of at least about 700° C. in less than one second to thermally decompose polymer substrate and to cause gaseous decomposition products of the polymer to form a large internal pressure and burst holes through said outer nickel layer,   c) discharging gases from the thermally decomposed polymer substrate through said holes through said outer nickel layer to leave a nickel structure, and   d) annealing said nickel structure to increase strength of said nickel structure.   
     
     
       11. The method of claim 10 wherein said heating includes exposing said nickel-coated polymer substrate to a temperature of at least 900° C. to anneal the nickel structure. 
     
     
       12. The method of claim 11 wherein said heating includes sending said nickel-coated polymer substrates through a continuous furnace and said annealing includes sending said nickel structure through a belt furnace. 
     
     
       13. The method of claim 10 wherein a protective insert maintains temperature of the nickel-coated polymer substrate below the melting temperature of the polymer prior to said heating. 
     
     
       14. The method of claim 10 wherein a protective insert maintains temperature of the nickel-coated polymer substrate less than about 200° C. prior to said heating. 
     
     
       15. The method of claim 10 wherein said heating is to a temperature of at least 800° C. 
     
     
       16. The method of claim 10 wherein said heating includes exposing said nickel-coated foam to a hot zone of a single furnace maintained at a temperature between about 800° C. and about 1200° C. 
     
     
       17. The method of claim 10 including the additional step of cooling said annealed nickel structure in an atmosphere not oxidizing to nickel.